I have a crack in my foundation that previous owners had filled with epoxy. The crack has opened up slightly at some point in the last 8 years. Is there anything I can do to determine (short of calling in a foundation company) if there are serious things going on with the foundation here? What can I do to assess what is going on?enter image description here

  • This looks like it's fairly close to the top of the wall. Have you tried digging a bit on the outside to see if the crack goes all the way through? – Eric Petroelje Feb 18 '20 at 20:59
  • @EricPetroelje unfortunately the garage slab is poured on the other side of the wall. Although I may be able to dig down on the portion of the crack picture on the right hand side. – Bill Feb 18 '20 at 21:02
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    The slab may be the cause if there is no room for expansion, all concrete eventually cracks, 2 kinds of concrete that is cracked and that will crack. I would put a tape measure up there and take a high res photo and check it in a year or more and see if it is changing. – Ed Beal Feb 19 '20 at 0:10

There are several issues: 1) location of crack, 2) horizontal crack and small vertical crack, 3) seismic zone where you live, 4) form ties

1) The crack appears in the top portion of your foundation. This means it’s probably from freeze-thaw issues. (If the crack was in the lower half of the wall, it could indicate a weak foundation wall that could be leaning and getting pushed in.)

Do you get water seeping in the crack? If so, it would be an indication that water is penetrating the wall and then freezing, which causes expansion and then cracks.

If so, you’ll need to dig up the area outside the cracks, apply a foundation sealer and then install a drainline to carry water away from the foundation.

2) A horizontal crack indicates freeze / thaw issues rather than settlement issues. That’s good for you.

3) You live in a high seismic zone. Concrete walls require additional reinforcement in your zone. I suspect that reinforcement has been installed, because there are no other horizontal cracks in the wall.

4) It seems unusual that the horizontal cracks go directly across where the form ties are located. Perhaps when the forms were removed a slight crack developed which now allows water to penetrate the wall and then freeze.

In summary: If it’s leaking, I’d do the outside repair (sealer and drainline) and if it’s not, you could monitor it and see if it gets worse. (Btw, I’d make sure downspouts are connected and drain away from the wall and make sure the ground slopes away from the house.)

  • Since the op said the garage slab is there I would guess not enough room for expansion is causing the crack. – Ed Beal Feb 19 '20 at 0:12
  • @EdBeal How can the wall crack from “expansion” without the wall being restrained at the top? (Btw, a wood connection is not a restraint, by code.) – Lee Sam Feb 19 '20 at 1:26
  • The wall above restrains the concrete wall to a point, the op mentioned the slab in a comment. If you don’t think this could be the cause you destroy your case fore freeze thaw cycles as they would be similar in lateral forces. – Ed Beal Feb 19 '20 at 14:47
  • @EdBeal Freeze - thaw has nothing to do with lateral forces. Lateral forces is an external force and freeze- thaw is an internal force (expansion of frozen water). – Lee Sam Feb 19 '20 at 16:21
  • So is an expanding adjacent slab. – Ed Beal Feb 19 '20 at 17:38

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